Disciplinary action - chargesheet for suppression of information of working in another PSU prior to my joining

I am working in a PSU since last 4 years. Suddenly, I got a chargesheet today for suppression of information of working in another PSU prior to my joining here. The allegation is true as didn't submitted NOC or go through proper channel. I simply submitted resignation letter without settling my bond for left over service-bond period and joined another PSU. Please suggest me how to reply to the chargesheet.

You have agreed that the allegations levelled against you is true. You may reply accordingly.

You have Nil Option except Stating the Facts, Honestly in your Written Reply to the Explanation Letter/Charge-Sheet issued to you.
You may add Why you did what you did (withholding Information) under the circumstnces while applying for and or Furnishing Facts while Joinging present Employment
Kritarth Team
Bengaluru Centre, 17 Dec 2019